The present invention relates to a variable displacement compressor with a decelerating mechanism and a method of inhibiting noise from producing in a variable displacement compressor.
Japanese Unexamined Patent Publication No. 11-264371 discloses a swash plate type variable displacement compressor for use in a vehicular air conditioner. In the compressor, torque of a drive shaft is transmitted to a swash plate through a rotor secured to the drive shaft and a hinge mechanism. A piston connects with the swash plate through a pair of shoes. As the piston reciprocates in a cylinder bore in accordance with rotation of the swash plate, refrigerant gas introduced into the compressor is compressed and is discharged. Also, the swash plate is configured to slide on the drive shaft and to tilt relative to the drive shaft. The inclination angle of the swash plate relative to the drive shaft varies by adjusting pressure in a crank chamber that accommodates the swash plate by a control valve. Thereby, stroke of the piston and displacement of the compressor vary.
In the above-mentioned variable displacement compressor, the inclination angle of the swash plate upon maximum displacement operation, that is, the maximum inclination angle is regulated by contacting a stopper portion of the swash plate with a receiving portion of the rotor. Therefore, noise produces due to contact upon contacting, particularly just after starting the compressor, that is, upon switching from an OFF-state to a state of the maximum displacement, the swash plate collides with the rotor at relatively high speed, and relatively large noise is produced. Particularly, in a compressor having three cylinders (relatively small number of cylinders), there are multiple swash plate collisions. Additionally, a spring for reducing the inclination angle that urges the swash plate to reduce its inclination angle is generally interposed between the swash plate and the rotor. The spring for reducing the inclination angle is directed to maintain the minimum inclination angle of the swash plate upon stop of the compressor. Therefore, the spring cannot inhibit the above-mentioned noise produced by collision of the swash plate at relatively high speed. Accordingly, it is desired that noise produced when the swash plate collides with the rotor is reduced and inhibited.